GT6 knock

[Guppy916]

Hi Guys, I have a MK3 GT6 which when I roll backwards out of gear, I get a faint knocking noise, so I thought UJ's or loose bolts, so I v'e been under the car checked the diff oil, gearbox oil, both ok, all nuts and bolts are tight, no play in the UJ's, but a little play in the sliding joint on the prop shaft but I can't see this as my problem, any ideas please 

is the prop a serviceable part or do i just buy a recon unit

[Clive]

You won't feel any play in a driveshaft UJ unless you undo the spring eye bolt. You may see a witness mark though if the uj cup is spinning in the yoke.

And this is definitely only in reverse? and a knock not a rubbing?  Which rear suspension is fitted? And what wheels/tyre size?

It may be worth getting the car up on decent axle stands, leaving the rear wheels on and getting an assistant turning them. That way you may be able to pin the noise down. Then again it may need the wheels in the on-road position, access to a pit may help then (you never know)

 

[Pete Lewis]

prop telescopes do wear quite badly  , its repairable if cut off and a replacement welded and balanced by a prop specialist 

buying a complete replacement is probably more ecconomical

is the knock from brake shoe contact with the drum ????

 

pete

[Guppy916]

Non Rotoflex guys,

Thats a good call Pete i shall drop the drums off and check for any rub marks

Clive the boss thinks she heard it once when we went round a 90 deg junction

15x175x55 I have a couple of rub marks on the front wheel arches, this only happens when i'm on full lock though,

Any ideas where to purchase a new prop shaft I've got Rimmer's at Part No.: 213151 £239 

[Gully]

I've seen people recommend Dave Mac Propshafts - they pop up in response to a Google search.

Gully

[Pete Lewis]

canley classics  £166 +Vat    213150/151

 

if its heard on corners its more likely drive shaft UJ with float . canley sell thicker circlips to solve this

( assuming the uj is sound )    

remember a prop turns around 4  times faster than the road wheels so  a prop knock frequency is much faster than a road wheel speed rotational  knock 

 

Pete

[Clive]

I believe Dave Mac makes them for CC, so just compare the 2 prices?

Possibly have alook at tie rod bushes, spring eye and so on. Changing the direction of movement reverses the normal forces.

Assuming long shafts, so shouldn't be wheel to tie-rod contact ( got that when I used 15" wheels on a herald based spartan)

 

[haggis]

Hi guppy, may be a long shot but just check there’s nothing rolling around the boot floor pan or rear seat pan, I had a problem yesterday where I thought I had a major problem and after 3 hours under the car found a can of Heineken from Le Mans rolling around in the back! ? you never know. Good place in Feltham London if you are south and want a good prop service. 

Hag 

[Guppy916]

Cheers Hag,  I've been talking to propshaft services in Feltam today, it definitely isn't a beer can as the only thing in the spare wheel well is the fuel pump and filter,  the noise is more a solid sound, than something rolling around lose, I see your in Hampshire , 

[Ian Foster]

Hi Guppy

Propshaft Services in Feltham, shortened and balanced a non OD shaft for me in about 1980, when I converted my GT6 to OD.

It's still on the car today about a 100k miles later, so they must have done a good job !.

Ian F

[Guppy916]

Hi guys, Paul has quoted about £100 +vat with a three day turn around, 

I think they are about an hours drive from me, so it's a no brainer I shall pop if off over the winter months so it's ready in the spring, or if the knock gets any worse i'll do it now